Lifting the U.S. ban on crude oil exports would lower consumer prices and stimulate further production from shale and other unconventional formations, ConocoPhillips CEO Ryan Lance told a Houston audience Tuesday.

The United States has increased its production of oil from unconventional plays in the last five years, but refining and pipeline limitations have created bottlenecks of crude that have lowered prices and discouraged production, Lance said during the 2013 Deloitte Oil and Gas Conference at the Hilton Americas-Houston.

Houston-based ConocoPhillips, the world's largest independent oil producer, recently has reported growth in its Eagle Ford Shale and Permian Basin holdings in Texas and the Bakken Shale in North Dakota.

Lance noted that those regions produce largely light, sweet crude, while most U.S. refineries are designed to process high-sulfur crude from Canada and South America.

That means the shale crude may be more attractive to overseas markets where refineries are equipped for it, he said.

"The world needs the crude," Lance said, "and there are places where we could export that crude into existing refineries."

Refining the lighter crude overseas would be more efficient for domestic consumers, because it would be cheaper to use those refineries overseas than to make the capital investments to retool the domestic refineries.

"It will ultimately give the consumer cheaper prices at the pump," Lance said. "I accept that it is going to be a pretty hard climb in D.C., but we need to start making the case for the economic benefits."

Since oil shortages in the 1970s, the U.S. generally has prohibited exports of crude while allowing overseas sales of refined products. Now, some lawmakers are suggesting easing the ban on crude exports.

In another session at Tuesday's conference, a senior Halliburton executive said the oil field services company will continue to make deals as the unconventional oil and gas business consolidates but will be selective.

It buys 10 to 15 companies a year and expects its level of spending to continue, Halliburton Chief Financial Officer Mark McCollum said.

But he said the company will be discerning about deals, looking hard at the value provided by a potential acquisition and how it fits into Halliburton's broader strategy.

Halliburton is focusing the search on new technologies that fit with its existing infrastructure, and for adjacent services and product lines that help complement existing services, McCollum said.

The company is also interested in investments that could help it move into new geographical areas, McCollum said, noting that the company is working on partnerships in China.

Oil field services has been the fastest-growing sector for deals in the energy industry, but upstream remains the most active for deals. Upstream accounted for $284 billion of the more than $400 billion spent on acquisitions and mergers in 2012, according to a Deloitte study last year.

Gary Halverson, vice president of Cameron International and president of Cameron Drilling & Production Systems, said at the Deloitte conference that his company continues to invest in acquisitions to expand its offshore services presence, but stressed that services companies can't buy their way into sustainable growth.

"Acquisition is not a strategy," said Halverson said. "The best way to do it is organically."

She used to be on the energy desk for the Houston Chronicle, covering a range of issues from BP's Deepwater litigation to electricity pricing to Chesapeake Energy's tumultuous finances. Emily previously covered the Financial Accounting Standards Board for Thomson Reuters and water finance for Global Water Intelligence. She has worked as a policy analyst for the Government Accountability Office and as a humanitarian auditor for CARE, where she travelled to Bosnia, Haiti, Mozambique and other far flung locations.

In her free time, Emily writes and plays music, and is still secretly hoping that her jazz rendition of "Living Life Post-Subprime" will one day top the charts.